Chemical Composition, Antimicrobial and Antioxidant Activities of Essential Oil and Methanol Extract from the Stems of Dasymaschalon rostratum Merr. & Chun

The present study provides the first information on the chemical composition, antimicrobial and antioxidant potentials of the essential oil and methanol extract from the stems of Dasymaschalon rostratum Merr. & Chun. Gas chromatography and gas chromatography-mass spectrometry analysis revealed that the main components of the D. rostratum essential oil were β-caryophyllene (27.4%), β-pinene (12.8%), α‑copaene (11.7%), α-pinene (8.4%), and α-humulene (6.2%). The antimicrobial assay showed that the essential oil had better activity against all tested microorganisms with lower minimum inhibitory concentration (MIC) ≤ 500 μg/mL compared with methanol extract. In turn, methanol extract was distinguished by the higher antioxidant potential in comparison to the essential oil in both DPPH and ABTS assays with IC50 values of 119.3 and 76.2 μg/mL, respectively. Furthermore, the total phenolic content of methanol extract was determined as 32.5 μg/mg. The results of the present investigation demonstrated significant variations in the antimicrobial and antioxidant activities of the essential oil and methanol extract from the stems of D. rostratum. In addition, complementary investigations should be conducted to identify phenolic compounds of these plant extracts as well as to evaluate the antimicrobial mechanisms of essential oil against bacteria and fungi.